Do you have more than one box?
If so, is it happening on all?
If not on all, try swapping boxes around to see if problem follows box or location.
Coax issue could be affecting all channels at times.
But if you are only watching one, you wouldn't know if it was affecting other channels.
I saw a post a while back where someone found that the coax had been chewed outside.
It came in under their deck and didn't notice until they started checking.
It could also be the box is starting to fail.
7232s are quite old.
